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DW6000 having trouble getting heard on 99W 1230???

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chriswlan
Ex Member


Aug 7th, 2009 at 6:19am  
Checking if the sat or gateway is giving trouble for anybody else?

For just a few days, late pm, I can usually get the "System" to slowly come on; but sometimes have a real hard time to get my browser moving.

Christian
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« Last Edit: Aug 7th, 2009 at 7:32pm by N/A »  
 
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USN - Retired
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Reply #1 - Aug 7th, 2009 at 11:43am  
I'm right next door on 99W/1250, haven't had any problems. Haven't heard any screams from other 1230 users either. Typical gateway congestion notwithstanding, I think the problem is likely a hardware problem your end.

When the System LED goes out, it's usually accompanied by either the RX or the TX (sometimes both). The DW6000 suggests that this is an older ODU (OutDoor Unit). It  becomes heat-sensitive over time, especially on a hot bright day. As the day cools - or the shade moves in to reduce the direct exposure - or it rains - the electronics often come back to life. So i what you're experiencing is slowly diminishing SQF numbers (received signal level) ending in the RX LED going out - or if you see an increasing number of transmission errors ending in the TX LED going out - your problem may be heat related

Next time that happens, spray the TRIA (the hardware on the arm) with a water hose for 2-3 minutes. If the connection comes back up, you've found the problem. Unfortunately the relief is temporary. The water hose trick simply proves that it's time to buy a new transmitter, a new LNB, or - just chuck it all and get a whole new TRIA (Transmit/Receive Integrated Assembly).

That said, Hughes no longer provides tech support for the DW6000, hasn't for quite some time now. You might simply consider upgrading to the HN9000S. All hardware gets replaced, indoors and out.

//greg//

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chriswlan
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Reply #2 - Aug 7th, 2009 at 7:17pm  
Hi Greg, tks for your time:

As I explained in my other post (can't see where it went????) it seems to me to be heat sensitive, BUT the other way:

My RX stats are perfect: not a single failed RX out of a quarter million... I had also repeaked the dish and gained a couple points above where it was when all was fine, weeks ago.

ALL the lights are ALWAYS on, including System (after a possible slow painful peak hour power up), it is just that the TX can be blinking REPEATDLY (apparently trying to be heard by the NOC or the Sat), before the RX finally give its own single blink (I assume when the NOC finally sends its ACK/NACK)

BUT it also seems to be related to time of day: peak late pm. So I was wondering if the above peculiar TX/RX led "dance" has any chance to be caused by traffic congestion? Before I tear into the hardware.

In normal "mixed" traffic all 3 RX TX and LAN seems to roughly alternate quite quickly, 3-way like.

When my problem shows up, the LAN goes quiet (waiting for the DW to be done?)  while the TX seems to blink endlessly by itself, trying to do its thing... After a little while (seconds), apparent success and the RX blinks once, on receiving the NOC's ACK/NACK (Nack likely, I'm sure!)...

STILL seems to me the Sat/NOC/Gateway could possibly cause this behavior?????????????? (this is my main question)

The only times when I seem to get a legit quickly repeated train of TX blinks are in a upload speed test, followed by a single RX blink; then repeated again until end of test. Same with a dnld speed test: a bunch of RX blinks before a single TX single blink... But of course speed tests are OUTSIDE the peak hours trouble.


I also found something on the 'net about the TX voltage:
telnet 192.168.0.1 1953
and I seem to read a constant hi-70's... Is this correct?

What is that TX voltage? Not the DC supply? Is it the measure of the ACTUAL RF output of the PA? I'll keep an eye on it.

Thanks again

Christian
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Reply #3 - Aug 7th, 2009 at 9:19pm  
I deleted the other post, no sense in talking about the same issue in two different places. And there is often no direct corelation between "reading it on the Internet" - and reality.

If you "peaked" your dish based upon SQF, then the job is only half done. The next step is to peak the ACP, then fine tune from there. If you stopped at SQF - for the time being you're the one who's likely responsible for some of the current throughput issues. Failing to proceed to the ACP and fine tuning stages results in a very pretty receive signal, and a crippled transmit signal. A crippled transmit results in excessive retransmissions, which subsequently serves to degrade receive productivity.

//greg//
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« Last Edit: Aug 8th, 2009 at 11:44am by N/A »  
 
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chriswlan
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Reply #4 - Aug 8th, 2009 at 7:23am  
Here is the latest:

===ACP: I didn't realize there could be minor differences in the pointing of the ACP peak and the SQF max. Indeed the SQF peak is broader on my old oval grey dish. Peaking the ACP is not easy as the value is buried in lots of "noise". Maybe the ACP peak was not concentric with the SQF peak, but in my case at least, it is quite a small difference, if anything at all. Wish DW has put in a Az adjust screw!

===After gaining just a few points on my ACP, I found the modem would have a hard time getting to "System", and not for long. Failed TX were now running 20 to 1!!! Also the ODU TX voltage was a bit lower yet at 69 or so...

===The sun was down, the air much cooler, so I tried playing the soft flame of a small propane torch on the ODU Transmitter case, at the Power Amplifier end...

And bingo! A solid system lite, with Failed TX "only" 1 to  Succeeded-2; and the ODU TX voltage a few points higher, same as yesterday at 76. Supposed to be 120's I understand.

I'll have to play this little game a few more times to confirm, but it is all pointing toward a very slowly dying Transmitter. I'm beginning to realize it might have started last fall even. So I'm starting to look for a spare, at least of the refurbished quality. Poking around the 'net, they seem to fail fairly often.

Tks to all

Christian
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Reply #5 - Aug 8th, 2009 at 11:34am  
Well, the older CHINON type TRIA (Transmit/Receive Integrated Assembly) has demonstrated a definite temperature sensitivity over time. But yours is the very first that I've heard about that was diagnosed with flame rather than water. Are you sure you don't have water in your waveguide instead?

CHINON is the flat rectangular TRIA, replacement components are becoming increasingly scarce. The later generations - TIGRIS/ISIS/OSIRIS/ANUBIS - seemingly have a more robust transmitter component, and are considerably more available on the internet. Since the LNB becomes temperature sensitive as well, you may want to consider a whole new TRIA and be done with it.

Isolation (ACP) by the way is first adjusted with a rotation of the reflector on its horizontal axis. Only after you've peaked the signal by rotating do you try to fine tune ACP with Az/El tweaks. It's a function of phase linearity. Improper alignment - particularly POL - will introduce phase distortion.

Note of caution: peaking ACP is quite often achieved at the expense of SQF, sometimes as many as 10 points. This is normal. Once the optimum ACP number has been achieved, do not make the mistake of trying to recover any of the "lost" SQF. Your receive has a far greater fade margin than does your transmit. It's imperative to maximize the transmit, even if it's at the expense of the receive.

I don't know of an azimuth fine tuning device for the standard Hughes reflectors. Matter of fact, my 98cm Prodelin doesn't have one either. My azimuth fine tuning is assisted by an application of weatherproof grease inside the pole cap. There is however a Direcway Elevation Alignment Tool. But it's pricey - about $80 I think. Installers carry one in their tool box, and take it from job to job. But they can be permanently mounted as well. The model name is DW-EL TOOL and the Hughes part number is 1029130-0403. If it interests you, I may have one of the early 74cm antenna brackets in the basement - the version that still has the integral elevation fine tune function.

//greg//
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